The present invention relates to automated mechanisms for applying fasteners. The present invention also relates to the use of such mechanisms in the panelized, modular and manufactured home industries and in related industries.
Historically, the construction of houses and other buildings that incorporate wood or wood like material consisted substantially of building a frame and attaching siding to the exterior of the frame and lathe and plaster or sheetrock to the interior of the frame. Each framing member was installed individually to form the completed frame and the siding and interior cover were then attached one member at a time to a completed frame.
In an effort to reduce the cost of home (or other building) construction, manufactured or mobile home techniques were developed. In some manufactured home facilities, whole walls (completed wall frames with exterior sheeting attached, with or without an interior covering) are constructed at once. The walls are then interconnected to form the finished house. Amongst other considerations, manufactured homes decreased costs with more efficient construction techniques, but produced houses that lacked desired variety or customized features.
The panelizing industry is emerging as a compromise between xe2x80x9cstick framexe2x80x9d construction and manufactured homes. Panelizing techniques attempt to provide customization, while providing some of the efficiencies found in manufactured home production. Panelizing facilities often include an assembly line in which forms for receiving studs are provided. A representative line may include a first station at which the studs are inserted into the form and fastened together into a wall panel frame (of a more manageable length than a manufactured home wall, e.g., often 4-12 feet). At a second station, exterior sheeting such as plywood or particle board may be applied (for an exterior wallbase). At a third and fourth station, respectively, a vapor barrier and siding may be applied, if appropriate. The various wall panels are then transported to a job site where they are lifted into place and secured.
Mechanisms used to apply fasteners during panel (or manufactured home wall) fabrication are often referred to as xe2x80x9cnail gunsxe2x80x9d or simply xe2x80x9cgunsxe2x80x9d and various gun arrangements are known. An example of the use of these guns in conventional wall panel formation is as follows. After a wall panel frame has been formed, sheeting or the like (for an exterior wall) is provided over the panel frame and a track assembly having a plurality of fixed position guns mounted thereon is lowered into position. The track is centered over a stud and the plurality of guns is fired causing a fastener to be driven from each gun through the plywood into the stud. The track assembly may then be positioned over the next stud, and the process is repeated. This track assembly with a plurality of guns may be hand-held (by one or more persons on each end) or formed integrally with automated machinery.
A disadvantageous aspect of prior art fixed position, multi-gun tracks, amongst others, is that they require a plurality of guns which are the most expensive part of the track assemblies. For example, if it is required to fasten every foot for a wall section eight feet in length, then nine guns are required. If it is required to fasten every 6 or 3 inches, then 17 or 33 guns are required, respectively. As applied to hand-held track assemblies, the provision of a plurality of guns is additionally disadvantageous in that it increases the weight of the assembly.
Another disadvantageous aspect of fixed position gun tracks is that since the guns are indeed fixed, it is undesirably difficult and time consuming to change their position to accommodate different panel frame configurations, or different spacing for siding or the like.
Other disadvantageous aspects of prior art track assemblies include that they utilize contact firing. Contact firing relies on mechanical activation and mechanical sensors having a higher rate of malfunction than, for example, electrical sensors. Contact fired guns also tend to have nail out problems where guns towards the top and bottom plate of a panel frame run out before xe2x80x9cinteriorxe2x80x9d guns that do not fire for window or door openings.
Accordingly, it is an object of the present invention to provide a track assembly that utilizes fewer guns without reduced performance.
It is another object of the present invention to provide a track assembly that incorporates an automatically moveable gun.
It is another object of the present invention to provide various drive mechanisms for a movable gun and to provide portable and non-portable track assembly embodiments.
It is also an object of the present invention to provide an improved gun suspension and to provide photoelectric electric or other non-mechanical sensors to detect various conditions that affect gun movement and firing.
These and related objects of the present invention are achieved by use of a track assembly having movable fastening mechanism as described herein.
The attainment of the foregoing and related advantages and features of the invention should be more readily apparent to those skilled in the art, after review of the following more detailed description of the invention taken together with the drawings.